The present invention relates to the protection of workers exposed to the risk of falling from considerable heights, more particularly in the building industry, and specifically relates to a fall preventing device having an instantaneous locking action.
Known fall preventing devices are generally constituted by a locking mechanism which is fixed to a member for connection to a harness or belt worn by the user by means of a connecting element, said mechanism co-operating with a retaining cord, rope or cable. These known devices are often provided with an unlocking push button operated by the user when he is moving at points a long way from the connecting point.
The known fall preventing devices are very reliable and they have a very short response time in the case of a fall. However, if the user operates the unlocking push button in order to carry out movements away from the connection point, his safety is compromised since at these times he is not protected. In addition, since the push button is readily accessible and easy to operate, there is a risk of an untimely operation of said push button by a reflex movement by the user's hand in the case of a fall or when he is unbalanced.
There are also fall preventing devices in which the manual unlocking push button is duplicated by an automatic locking mechanism. However, the known automatic devices in which unlocking is brought about by the action of a return spring have a certain inertia and as a result there is a relatively long length of fall, followed by sudden deceleration which can cause a painful shock or injury to the user's body.